This invention relates to computer enclosures.
Most computers require that air ventilation holes be placed at various locations around the chassis for cooling purposes. Indeed, to provide maximum cooling efficiency and to facilitate numerous mounting options for the chassis, it is desirable to provide ventilation holes on as many surfaces of the chassis as possible. Unfortunately, other considerations also apply that make the location of ventilation holes difficult. For example, computers in the United States must meet requirements of the United Laboratories concerning fire safety. Specifically, reasonable steps must be taken to ensure that flaming particles within a computer may not freely fall through openings in the bottom of a computer. For this reason, it was previously thought that ventilation holes could not be placed on the bottom of a computer, because to do so would potentially allow flaming particles to exit the computer from the bottom.
In one aspect, the invention includes a fire shield that may be mounted over air ventilation holes on the bottom of a computer chassis. The fire shield may include at least one offset for holding a fire-impenetrable surface away from the air ventilation holes of the computer chassis. The surface blocks a path that passes through the ventilation holes and extends orthogonally outward from the computer chassis, thus preventing flaming particles that exit the air holes from passing beyond the shield. The shield also establishes an air cavity that is in fluid communication with the air holes in the computer chassis and with ambient air for cooling purposes.
In another aspect, the fire shield may be constructed of sheet metal. First and second elongate folds in the sheet metal may be used to create the offset and establish the air cavity. Hooks may be provided along the first elongate fold to engage the air holes. A clearance hole may be provided on the second elongate fold to receive a fastener such as a screw. Once the hooks are engaged with the air holes and the screw is attached, the shield will be retained against the chassis even when the shield is on the bottom side. The air cavity may vent to ambient air on either end of the shield between the two elongate folds.